#(x^2+5)/(2x)=5#
#x^2+5=2x*5#
#x^2+5=10x#
#x^2-10x+5=0#
#"This is a quadratic function .We should find the roots of the function."#
#"if "ax^2+bx+c=0#
#Delta=sqrt (b^2-4ac)#
#"Where "a=1" , "b=-10" , "c=5#
#Delta=sqrt((-10)^2-4*1*5)=sqrt(100-20)=+-sqrt(80)#
#x_1=(-b-Delta)/(2a)=(10-sqrt 80)/(2*1)=(10-4sqrt5)/2=5-2sqrt5#
#x_1=(-b+Delta)/(2a)=(10+sqrt 80)/(2*1)=(10+4sqrt5)/2=5+2sqrt5#